Luminescent, Three-Coordinate Azadipyrromethene Complexes of d<sup>10</sup> Copper, Silver, and Gold

Boron azadipyrromethenes are red-light-absorbing dyes with chromophoric capabilities deriving from a conjugated, chelating framework. Reported here are tricoordinate copper(I), silver(I), and gold(I) complexes of a tetraphenylazadipyrromethene ligand. The new complexes are characterized by optical absorption and emission spectroscopy, multinuclear NMR, mass spectrometry, elemental analysis, and X-ray diffraction crystallography. Time-dependent density functional theory calculations indicate that the principal absorption features in azadipyrromethene complexes result from optically allowed intraligand transitions that undergo configuration interaction.